Vulcanizing elastomers and crosslinking, plastomers with organic tetraperoxides

ABSTRACT

Tetraperoxides of the formula   WHERE X is a bivalent radical such as alkylene; R1 is hydrogen or an organic radical; R2 is alkylene allkoxy carbonyl; and R3 is an organic radical. Method of preparing tetraperoxides by addition reaction between a bis-hydroperoxide and a carbonyl compound to form a dihydroxy diperoxide, followed by condensation of the dihydroxy diperoxide with a tertiary monohydroxide. The tetraperoxides are useful for vulcanizing saturated elastomers, crosslinking plastomers, and initiating radical polymerization.

United States Patent Sacrini et al.

[451 Apr. 15, 1975 VULCANIZING ELASTOMERS AND CROSSLINKING, PLASTOMERS WITH ORGANIC TETRAPEROXIDES Inventors: Egeo Sacrini; Claudio Cavallotti,

both of Milan, Italy The B. F. Goodrich Company, Akron, Ohio Filed: June 27, 1973 Appl. No.: 374,268

Related U.S. Application Data Division of Ser. No. 62,l28, Aug. 8, 1970, Pat. No. 3,775,465.

Assignee:

Foreign Application Priority Data Aug. 12, 1969 Italy 20839/69 U.S. Cl 260/42.42'; 252/1883 R; 260/88.2; 260/94.9; 260/475 SC; 260/610 R Int. Cl.... C07c 73/00; C08f 47/00; C08f 45/08 Field of Search 252/1883 R; 260/610 R, 260/42.42,-475 SC, 88.2, 94.9

References Cited UNITED STATES PATENTS 4/l966 Bafford 260/42.42

ll/l969 6/1972 Bucci 260/42.42 Usamoto 260/42.42

Primary Examiner-Benjamin R. Padgett Assistant Examiner-Irwin Gluck Attorney, Agent, or Firml-lubbell, Cohen & Stiefel [57] ABSTRACT Tetraperoxides of the formula 11 Claims, No Drawings VULCANIZING ELASTOMERS AND CROSSLINKING, PLASTOMERS WITH ORGANIC TETRAPEROXIDES This is a division of application Ser. No. 62.128. filed Aug. 8, 1970 now U.S. Pat. No. 3,775,465.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a new series of organic peroxides. More particularly, it relates to a process for the preparation of peroxides having four peroxidic functions, to novel peroxides having four peroxidic functions, and to the use of such peroxides as radical polymerization initiators, vulcanizing agents for elastomers, crosslinking agents for plastomers-and as organic reactants.

2. Description of the Prior Art It is well known that organic compounds of a peroxidic nature are important as generators of free radicals and consequently initiators of free radical polymerizations, as crosslinking agents for plastomers and as vulcanizing agents for elastomers.

THE INVENTION The present invention provides a particular type of new organic peroxides having good stability and low volatility at temperatures above room temperature. such peroxides being particularly suitable for use as both vulcanizers for elastomers and as crosslinking agents for plastomers.

The present invention provides a new series of organic peroxides characterized by the presence of four peroxidic groups. these peroxides having the formula:

wherein:

each of R, is hydrogen; alkyl, haloalkyl. cycloalkyl, halocycloalkyl or alkyleycloalkyl groups having 1-15 carbon atoms; aryl, haloaryl or alkaryl groups having 6-15 carbon atoms; oxyalkyl, oxyalkylaryl or oxycycloalkyl groups having lcarbon atoms; each of R is carbalkoxy alkylene wherein each alkylene group and each alkoxy group has 1 to 4 carbon atoms such methylene ethoxy carbonyl,

0 OHIOEIOH-OHP or the like;

each of R is alkyl or haloalkyl groups having 4-12 carbon atoms; cycloalkyl, halocycloalkyl or alkylcycloalkyl groups having 4-21 carbon atoms; aryl, alkaryl or haloaryl groups having 6-24 carbon atoms; oxyalky], oxyalkylaryl or oxycycloalkyl groups having 4-24 carbon atoms; or an acyl group having 6-12 carbon atoms; preferred groups being tertiary alkyl such tert.-butyl, tert.-amy1, and cumyl; and

X is alkylene, haloalkylenc or arylalkylene groups having 2-18 carbon atoms; alkenylene, haloalkenylene or arylalkenylene groups having 2-18 carbon atoms; alkinylene, haloalkinylene or aryl alkinylene groups having 2-18 carbon atoms; oxyalkylene groups having 2-12 carbon atoms; arylene, alkyl arylene or halo arylene groups having 6-18 carbon atoms.

Examples of specific compounds of the above cited general formula include:

1. a-a'-['2-tert.-butyl peroxy-(3-ethoxycarbony1)- isopropylidene-2-peroxy]-1,3-diisopropylbenzene,

a-a'-[2-tert.-butyl peroxy-(3-ethoxycarbonyl)- isopropylidene-Z-peroxy]-1,4-diisopropylbenzene,

3. a-a'-[2-cumyl peroxy-( 3-ethoxycarbony1 isopropylidene-Z-peroxy]-1,3-diisopropylbenzene,

4. a-a'-[2-cumyl peroxy-(3-ethoxycarbonyl)- isopropylidene-Z-peroxy]-l ,4-diisopropy1benzene.

The peroxides of this invention have the unusual properties of being endowed with good stability and low volatility at temperatures higher than room temperature. These properties permit the compounds to be readily incorporated into both plastomers as crosslinking agents, and elastomers as vulcanizing agents, without giving rise to troublesome secondary phenomena.

This invention provides, moreover, a process for the preparation of the foregoing peroxides, as well as of other known tetraperoxides, e.g., those disclosed in U.S. Pat. 3,489,730 at column 1, lines 41-59, the contents of which are incorporated herein by reference, through two successive steps. In the first step there occurs an addition reaction between a bis-hydroperoxide and a carbonyl compound, with the formation of a diperoxide having a double hydroxy function. In the second step there occurs a condensation reaction between the previously obtained diperoxide and a tertiary mono-hydroperoxide.

According to a preferred embodiment. the desired tetraperoxides are prepared in the presence of a suitable solvent by reacting, in the first step 1 an organic carbonyl compound of the formula: R,COR wherein each of R, and R are hydrogen; alkyl. haloalkyl, cyeloalkyl, halocycloalkyl or alkylcycloalkyl groups having 1-15 carbon atoms; aryl, haloaryl or alkaryl groups having 6-15 carbon atoms; oxyalkyl, oxyalkylaryl or oxycycloalkyl groups having 1-15 carbon atoms; R: may also be an carbalkoxy alkylene wherein each alkylene group and each alkoxy group has 1 to 4 carbon atoms; or R, and R together with the central carbon atom form a cycloaliphatic ring, having 4-16 carbon atoms, said ring being alkyl, halogen, or hy droxy substituted and having l-8 carbon atoms, with (2) a bis-hydroperoxide of the formula: HOO-X- OOH, wherein X is as defined above, the reaction being carried out in the presence of a suitable dehydrating agent and an acid catalyst, at a temperature of from about to +80 C., preferably from about 1() C. to C.

The compound thus obtained is a diperoxide of the formula: 1

. a-oz'-[2-hydroxy(3-ethoxycarbonyl)- isopropylidene-Z-peroxyll ,3-diisopropylbenzene;

f. a-a-( 1-hydroxy-cyclopentylidene-l-peroxy)-1 .3-

diisopropylbenzene;

g. a-a-( 1-hydroxy-cyclopentylidene-l-peroxy)-l ,4-

diisopropylbenzene;

h. a-a'-( l-hydroxy-cyclohexylidene-1-peroxy)-l .3-

diisopropylbenzene;

i. a-a'-( l-hydroxy-cyclohexylidenel peroxy)-l .4-

diisopropylbenzene;

j. a-a-(l-hydroxy-4-tert.-butyl-cyclohexylidene-lperoxy)-1.3-diisopropylbenzene;

k. oz-a-(1-hydroxy-4-tert.-butyl-cyclohexylidene-lperoxy )-l .4-diisopropylbenzene;

I. a-a-( l-hydroxy-cyclododecylidene-l-peroxy)-1.3-

diisopropylbenzene;

m. a-oz'-(1-hydroxy-cyclododecylidene-l-peroxy)- l,4-diisopropylbenzene;

n. a-a'-(2-hydroxy-n-butyliden-2-peroxy)-1,3-diisopropylbenzene;

o. a-a'-(4-hydroxy-2,6,8-trimethyl peroxy)-1.3-diisopropylbenzene;

p. a-a'-[ 2-hydroxy-( 3-phenyl )-propylidene-2- peroxy ]-l .3-diisopropy1benzene.

The peroxides defined by the foregoing formula are new compounds. and are useful as initiators of radical polymerizations.

The diperoxides obtained as described above are then reacted in the second step of the process. with monohydroperoxides in the presence of suitable dehydrating agents and acidic catalysts at a temperature between about 30 and +80 C.. preferably between about l and +50 C.

Examples of bis-hydroperoxides which are suitable for use in the first step of the process include:

diisopropylbenzene- 1 .3-dihydroperoxide;

diisopropylbenzene-l .4-dihydroperoxide; 2 -dimethyl-2,5-dihydroperoxy-hexane; 2.5-dimethyl-2.5-dihydroperoxide-hexene-B; 2.S-dimethyl-2.5-dihydroperoxy-hexyne-3; etc.

Examples of carbonyl compounds suitable for use in the first step of the process include: aliphatic ketones such as methyl ethyl ketone. acetone; substituted aliphatic ketoncs such as ethyl-acetocetate; cycloketones such as cyclopentanone, cyclohexanone and cyclododecanone; cycloalkylketones such as 4 terbutyl cyclohexanone; alkylarylaldehydes such as cinnamaldehyde; alkylheterocyclic aldehydes such as furyl acrylic aldehyde.

The mono-hydroperoxides which may be used in the second step of the process are of the type: R;,OOH wherein R is as defined above, preferably wherein a tertiary carbon atom is bound to the hydroperoxide group. Examples of such mono-hydroperoxides include: tert.-butyl hydroperoxide and substituted tert.- butyl hydroperoxides. cumyl hydroperoxide and substituted cumyl hydroperoxides. methyl-cyclohexyl hydroperoxide. 2 methyl 2-hydroperoxide-butyn-3, menthane hydroperoxide, etc.

Solvents suitable for use in this invention include linear aliphatic hydrocarbons having 6-10 carbon atoms; linear aliphatic halogenated hydrocarbons having 1 or 2 carbon atoms and l to 4 chlorine atoms cycloaliphatic hydrocarbons having 6-10 carbon atoms aromatic hydrocarbons having 6-9 carbon atoms. which may be halogenated with l to 2 chlorine atoms ethers for instance, ethyl ether.

nonylidene-4- The molar ratio between the bis-hydroperoxide and the carbonyl compound used in the addition reaction should be between 1:1.2 and'l:l0. and preferably between 1:1.5 and 1:5. Catalysts of an acid nature may be of the HCl. H SO and HClO type.

For the second step of the process, wherein a condensation reaction takes place, the molar ratio of diperoxide having a double hydroxy function to monohydroperoxide should be between 1:2 and 1:10, and preferably between 1:3 and 1:5.

As previously noted. the overall process of this invention can be employed to prepare a wide variety of tetraperoxides, many of which are known and many of which are new. Examples of tetraperoxides which can be made by the process of this invention include the following:

1. a-a'-(2-cumyl peroxy-isopropylidene-2-peroxy)- 1,3-diisopropylbenzene;

2. a-a'-(2-cumyl peroxy-isopropylidene-2-peroxy)- 1,4-diisopropylbenzene;

3. a-a-(2-tert.-butyl-peroxy-2-phenyl ethyl-Z-idene- 2-peroxy)-l ,3-diisopropylbenzene;

4. a-a'-(2-tert.-butyl-peroxy-2-phenyl ethyl-2-idene- 2-peroxy)-1,4-diisopropylbenzene;

5. a-a'-(2-cumyl peroxy-2-phenyl ethyl-Z-idene-Z- peroxy-1,3-diisopropylbenzene;

6. a-0z'-(2-cumyl peroxy-Z-phenyl ethyl-2-idene-2- peroxy)-1.4-diisopropylbenzene;

7. a-oz-[2-tert.-butyl peroxy-( 3- ethoxycarbonyl)isopropylidene-Z-peroxy1-1,3- diisopropylbenzene;

8 a-a'-[2-tert.-butyl peroxy-( 3- ethoxycarbonyl)isopropylidene-Z-peroxy]-1.4- diisopropylbenzene;

9. a-a'-[2-cumyl peroxy-(3-ethoxycarbonyl)- isopropylidene-Z-peroxy]-1,3-diisopropylbenzene;

10. a.a'-[2-cumyl peroxy-(3-ethoxycarbonyl)- isopropylidene-Z-peroxy ]-l ,4-diisopropylbenzene;

l1. a-a-(1-tert.-butyl peroxy-cyclopentylidene-lperoxy )-l .3-diisopropylbenzene;

12. a-a'-(1-tert.-butyl peroxy-cyclopentylidene-lperoxy)-1.4-diisopropylbenzene;

13. a-a'-(1-cumyl peroxy-cyclopentylidenel peroxy)-1.3-diisopropylbenzene;

l4. a-a-( l-cumyl peroxy-cyclopentylidene-1- peroxy)-l ,4-diisopropylbenzene;

l5. a-a-(l-tert.buty1 peroxy-cyclohexylidene-1- peroxy)-1,B-diisopropylbenzene;

l6. a-a'-( l-tert.-butyl peroxy)-1,4-diisopropylbenzene;

l7. a-a-( l-cumyl peroxy-cyclohexylidene-lper0xy)- l .3-diisopropylbenzene;

18. a-a'-(1-cumyl peroxy-cyclohexylidene-lperoxy )-l .4-diisopropylbenzene;

l9. oz-a'-( l-tert.-butyl peroxy-4-tert.-butylcyclohexylidene-1-peroxy)-l .3-diisopropylbenzene; 4

20. a-a'-( 1-tert.-butyl peroxy-4-tert.-butylcyclohexylidene-l-peroxy)-1,4-diisopropylbenzene;

21. a-a-(l-tert.-butyl peroxy-cyclododecylidene-lperoxy l .3-diisopropylben2ene;

22. a-a'-(l-tert.butyl peroxy-cyclododecylidene-lperoxy)-1,4-diisopr0pylbenzene;

23. a-a-( 2-tert.-butyl peroxy-n-butylidene-Z- peroxy l ,3-diis0propylbenzene;

peroxy-cyclohexylidene- 1 24. oz-a'-(4-tert.-butyl peroxy-2.6.8-trimethyl nonylidene-4-peroxy)-1,3-diisopropylbenzene:

25. a-a'-[2-tert.-butyl peroxy-(3-phenyl) propylidene-2-peroxy1-1.3-diisopropylbenzene:

26. a-a'-[ 1-cumyl-peroxy-(4-tert.-butyl) cyclohexylidene-l-peroxy1-l ,3-diisopropylbenzene.

Both the hydroxyl diperoxides and the tetraperoxides obtained according to this invention are soluble in aliphatic and aromatic hydrocarbons. chlorinated aliphatic and aromatic solvents, aliphatic alcohols. and aliphatic esters.

According to another and particularly interesting aspect of this invention, it has been found that the peroxides of this invention are excellent vulcanizing agents for saturated elastomers, crosslinking agents for plastomers, and as initiators for radical polymerizations.

vulcanization of ethylene-propylene copolymers is carried out at a temperature between about 140 and 190 C.. preferably between about 150 and 180 C.,

for periods of from about 5 to 200 minutes, preferably between about 5 and minutes.

The concentration by weight of the peroxide should be between about 0.5% and 10%, preferably between about 2% and 5%, based on the elastomer.

A particularly suitable vulcanization recipe is the following:

Parts Ethylene/propylene copolymer 100 Carbon black -80 ZnO l l Sulfur 0. l 5-0.5 Peroxide 0005-0112 The use of the peroxides of the invention as crosslinking agents for plastomers finds specific application for polyolefins, paraticularly polyethylene. inasmuch as its mechanical resistance at high temperatures is improved, its brittleness at low temperatures is decreased, and its solubility in aliphatic hydrocarbons, aromatic hydrocarbons, and chlorinated hydrocarbons is decreased. Moreover, the resistance of the polymer to light. weather and aging is improved.

The crosslinking is carried out at a temperature between about 100 and 200 C., preferably between about 145 and 165 C., at a pressure between about 50-200 kg./cm. for a period of time of from about 5 to 60 minutes, preferably from about 10 to minutes.

The concentration by weight of the peroxide is between about 0.5 and 10%, preferably between about 2 and 5%, based on the plastomer.

The most significant advantages offered by the use of the peroxides according to this invention in the vulcanization of saturated elastomers and in the crosslinking of plastomers. are:

1. The capability of obtaining virtually odorless vulcanized and crosslinked products;

2. Absence of blooming phenomena;

3. Short vulcanization times and low vulcanization temperatures;

4. Improved effectiveness remains unchanged even in the presence of conventional additives such as fillers, reinforcing agents, additives. co-agents. plasticizers, pigments and anti-oxidants.

The following examples further illustrate the invention. All parts are by weight unless otherwise stated.

EXAMPLE 1 200 cc. of ethyl ether, 60.6 g. of 1,3- diisopropylbenzene-bis-hydroperoxide-sodium salt at 67%, 51 g. of cyclopentanone at 99% and 20 g. of ground anhydrous calcium chloride. were introduced into a flask provided with astirrer.

This mixture was cooled to from 15 to 10C. and over a 20 minute period there were slowly introduced 60 g. of HCl at 36%. The mixture was then stirred for 1 hour at -5 C. The ether solution was then washed with water and treated with anhydrous sodium sulfate.

The a,a-( l-hydroxy-cyclo pentylidene-1-peroxy)- 1.3-diisopropylbenzene thus obtained (53 g. determined analytically) had the following characteristics:

lodometric titer: 98%

Half life: 30 minutes at 98 C.

Decomposition temperature: 45 C.

C (percent): found 66.40 (calculated 66.98)

H (percent): found 8.2 (calculated 8.69)

In a 10% toluene solution after hrs. at 40 C. no degradation occurred.

EXAMPLE 2 53 g. of a,a-(1-hydroxy-cyclopentylidene-lperoxy)-1,3-diisopropylbenzene obtained according to Example 1 and dissolved in 200 cc. of ethyl ether. 44 g. of tert. butyl hydroperoxide at 80%. and 40 g. of ground anhydrous calcium chloride, were introduced into a flask provided with a stirrer.

The ether solution was then cooled to 10 C. and over a 5 minute period there were introduced 20 g. of hydrochloric acid at 36%. The temperature was permitted to rise to 0 C. and the solution was stirred for 1 hour at 0 C.

EXAMPLE 3 300 cc. of ethyl ether, 41.8 g. of 1,4-diisopropylbenzene bis-hydroperoxide at 97.3%, 37.8 g. of 4-tert-butylcyclohexanone at 98%. and 18 g. of ground anhydrous calcium chloride were introduced into a flask provided with a stirrer.

The mixture was then cooled to 0 C. and over a 5 minute period there were introduced 24 g. of HCl at 36%. The temperature was maintained at 0 C. and the mixture was kept under stirring for 1 hour.

The ether solution was then washed with water and then concentrated under vacuum. avoiding completely evaporation of the ether.

The a-a-( l-hydroxy 4 tert.-butylcyclohexylidene- 1 peroxy)-1,4-diisopropylbenzene thus obtained (66 g. determined analytically) was kept in solution so as to be ready for subsequent reaction. and had the following characteristics:

lodometric titer: 98.5%

Decomposition temperature: 62 C.

Half-life at 112 C.: 30 minutes C (percent): found 70.4 (calculated 71.87)

H (percent): found 10.1 (calculated 10.18)

EXAMPLE 4 150 g. of ether solution containing 66 g. of a-a-( 1- hydroxy 4 tert.-butyl-cyc1ohexylidene-l-peroxy)- 1.4-diisopropylbenzene obtained according to Example 3. 44 g. of tert. butyl hydroperoxide at 80%. and 42 g. of ground anhydrous calcium chloride were introduced into a flask provided with a stirrer.

The solution was then cooled to 5 C. and over a 5 minute period there were introduced 30 g. of HCl at 36%. Care being taken not to exceed C.. the solution was then left under stirring at this temperature for 1 hour. The ether phase was washed with water. then with NaOH at and then again with water.

The solvent was subsequently removed under vacuum at 30 C.. thereby obtaining a residue (76 g.) identified as a-a'-( l-tert.-butyl-peroxy 4 tert.-butylcyclohexylidcne-1-peroxy)-1.4-diisopropylbenzene and having the following characteristics:

Melting point: 3234 C.

lodomctric titer: 99.8%

Decomposition temperature: 109 C.

Half-life at 121 C.: 30 minutes C (percent): found 69.6 (calculated 70.75)

H (percent): found 10.5 (calculated 10.40)

EXAMPLE 5 200 cc. of benzene. 81 g. of 1.3-diisopropylbenzenebishydroperoxide-sodium salt at 67%. 33.5 g. of cyclohexanone at 99%. and g. of ground anhydrous calcium chloride were introduced into a flask provided with a stirrer.

The mixture was then cooled to 10 C. and over a period of minutes there were slowly introduced 80 g. of HCl at 36%. The mixture was then left under stirring for 1 hour at 5 C.

The benzene solution was then washed with water and thereafter was dehydrated with anhydrous sodium sulfate.

The a-a'-(1-hydroxy-cyclohexylidene 1 peroxy)- 1.3-diisopropylbenzene thus obtained (71 g. determined analytically) was maintained in solution. This product had the following characteristics:

lodometric titer: 98%

Decomposition temperature: 55 C.

Half-life at 115 C.: 30 minutes C (percent): found 68.0 (calculated 68.22)

H (percent): found 9.0 (calculated 9.07)

EXAMPLE 6 lnto a flask fitted with a stirrer were introduced 71 g. of oz-a( 1-hydroxy-cyclohexylidene-l-peroxy)-1.3- diisopropylbenzene dissolved in 200 cc. of benzene (obtained according to Example 5). 58 g. of tert.-butyl hydroperoxide at 80%. and 45 g. of ground anhydrous calcium chloride.

The benzene solution was cooled to 1 0 C. and over a 5 minute period there were introduced 27 g. of hydrochloric acid at 36%. The solution was then left under stirring for 1 hour at 5/0 C. The organic phase was then washed. first with water. then with NaOH at 5%. and then again with water.

The benzene solution was then filtered on a layer of anhydrous sodium sulphate and celite and the solvent was removed under vacuum at 30 C.

Thereby were obtained 91 g. of a product identified as a-a'-( 1tert.-butyl-peroxy-cyclohexylidene-1 peroxy)-1.3-diisopropylbenzene. The product had the following characteristics:

lodometric titer: 98.5%

Decomposition temperature: 113 C.

Half-life at 135 C.: 31 minutes C (percent): found 67.5 (calculated 67.81)

H (percent): found 9.6 (calculated 9.6)

EXAMPLE 7 Into a flask provided with a stirrer were introduced 200 cc. of benzene, 50 g. of 1,3-diisopropylbenzenebishydroperoxide (sodium salt) at 60%. 15.8 g. of methylethylketone. and 30 g. of ground anhydrous calcium chloride. The mixture was cooled to 5 to 0 C. and over a 30 minute period there were then slowly introduced 49 g. of HCl at 36%. The mixture was then stirred for 1 hour at 0 C. The benzene solution was washed with water and then dehydrated with anhydrous sodium sulfate.

The a-a'-(2hydroxy-n-butyliden-Z peroxy)-1.3- diisopropylbenzene thus obtained (37 g. determined analytically) had the following characteristics:

lodometric titer: 97%

Decomposition temperature: 50 C.

Half-life at 122 C.; 30 minutes C (percent): found 65.3 (calculated 64.84)

H (percent): found 9.1 (calculated 9.25)

EXAMPLE 8 lnto a flask provided with a stirrer were introduced 37 g. of a-a'-(2-hydroxy-n-butyliden2-peroxy)1.3- diisopropylbenzene (obtained according to Example 7). dissolved in 200 cc. of benzene. 40 g. of tert.-butyl hydroperoxide at and 40 g. of ground calcium chloride. The benzene solution was then cooled to 5 C. and over a 10 minute period there were introduced 30 g. of hydrochloric acid at 36%. The temperature was allowed to rise to +5 C. and the solution was stirred for 1 hour at this temperature. The benzene phase was then washed with water. then with NaOH at 5%, and again with water.

The solvent was then removed under vacuum at 30 C.. thereby obtaining 39.5 g. ofa slightly straw-colored liquid residue identified as a-a-(2- tert.-butyl-peroxyn-butyliden 2 peroxy)-1.3-diisopropylbenzene. This product had the following characteristics:

lodometric titer: 94.6%

Decomposition temperature: 105 C.

Half-life at 114 C.: 30 minutes C (percent): found 65.8 (calculated 65.34)

H (percent): found 9.7 (calculated 9.79)

EXAMPLE 9 lnto a flask provided with a stirrer were introduced cc. of benzene. 100 g. of 1.3-diisopropylbenzenebishydroperoxide (sodium salt) at 60%. ,81 g. of

2.6.8-trimethyl-4-nonanone and 30 g. of ground anhydrous calcium chloride. The mixture was then cooled to 5 C. to C.. and over a 30 minute period there were introduced 95 g. of hydrochloric acid at 36%. The temperature rose to C. and the mixture was then left under stirring for 1 hour. The benzene phase was then washed with water and then treated with anhydrous sodium sulfate.

The a-oz'-(4-hydroxy-2.6.8trimethyl-nonylidene4- peroxy)-1.3-diisoprophylbenzene thus obtained 1 15 g. determined analytically) had the following characteristics:

lodometric titer: 94%

Decomposition temperature: 67 C.

Half-life at 107 C.: 30 minutes C (percent): found 71.7 (calculated 72.68)

H (percent): found 10.9 (calculated 11.18)

EXAMPLE 1 g. of a-a'-(4-hydroxy-2.6.8-trimethylnonylidene4-peroxy)-1,3-diisopropy1benzene (obtained according to Example 9) dissolved in 100 cc. of benzene. 79.5 g. of tert. butyl hydroperoxide at 75%. and 40 g. of ground anhydrous calcium chloride were introduced into a flask provided with a stirrer.

The solution was then cooled to 5 C. and over a 10- minute period there were introduced 40 g. of hydrochloric acid at 36%. Due to the exothermic reaction. the temperature rose to +5 C. and the solution was then left under stirring at +5 C. for 1 hour.

The benzene phase was washed with water. then with NaOH at 5%. and again with water. The solvent was then removed under vacuum at 30 C., thereby obtaining a liquid residue ofa slight brownish color which was identified as a-a'-( 4-tert.-butyl-peroxy-2.6,8- trimethy1nonylidene-4-peroxy)-1.3-diisopropylbenzene. which product had the following characteristics:

lodometric titer: 92%

Decomposition temperature: 109 C.

Half-life at 116 C.: minutes C (percent): found 71.3 (calculated 71.50)

H (percent): found 11.1 (Calculated 11.18)

EXAMPLE ll Into a flask provided with a stirrer there were introduced 300 cc. of benzene. 65.4 g. of 1.4- diisopropylbenzene-bis-hydroperoxide at 95%. 50 g. of cyclododecanone. and 50 g. of ground anhydrous calcium chloride.

The mixture was then cooled to 10 C. and over a 25 minute period there were introduced 60 g. of hydrochloric acid at 36%. The mixture was stirred for 1 hour at +5 C. The benzene solution was then washed with water and thereafter was dehydrated with anhydrous sodium sulfate.

The a-a'-( 1hydroxycyclododecylidene-1peroxy 1.4-diisopropylbenzene thus obtained (80 g. determined analytically) had the following characteristics:

lodometric titer: 98%

Decomposition temperature: 59 C.

Half-life at 114 C.: 30 minutes C (percent): found 73.3 (calculated 73.17)

H (percent): found 10.3 (calculated 10.58)

EXAMPLE 12 Into a flask provided with a stirrer were introduced 80 g. of a-a( 1hydroxy-cyclododecylidene-lperoxy)-1.4-diisopropylbenzene (obtained according to Example 11) dissolved in 300 cc. of benzene. 66.7 g. of tert.-butyl-hydroperoxide at 66.7%. and 40 g. of ground anhydrous calcium chloride. The benzene solution was then cooled to 0 C. and over a 10 minute period there were introduced 5 g. of hydrochloric acid at 36%.

The temperature was then allowed to rise to +5 C. and the solution was then stirred for 1 hour at this temperature (+5 C. The benzene phase was then washed with water. with NaOH at 5%, and then again with water.

The solvent was then removed under vacuum at 40 C., thereby obtaining 48 g. of a yellow liquid residue identified as a-a-( l-tert.-butyl-peroxycyclododecylidene- 1 peroxy )-1 .4-diisopropylbenzene. The product had the following characteristics:

Iodometric titer: 99%

Decomposition temperature: 109 C.

Half-life at 120 C.: 30 minutes C (percent): found 70.2 (calculated 71.89)

H (percent): found 10.9 (calculated 10.7)

EXAMPLE 13 Into a flask provided with a stirrer. were introduced 50 cc. of benzene. 50 cc. of ethyl ether. 60.6 g. of 1.3- diisopropyl-benzene-bis-hydroperoxide (sodium salt) at 67%. 27.7 g. of benzyl-methyl-ketone at 97%. and 30 g. of ground anhydrous calcium chloride. This mixture was then cooled to 15 C. and then were slowly added. over a 30 minute period, 60 g. of HCl at 36%. Thereafter the mixture was kept under stirring for 1 hour at 5 C.

The organic solution thus obtained was then washed with water and then was dehydrated with anhydrous sodium sulfate. The product thus obtained (37 g. determined analytically), identified as alpha-alpha'-[2- hydroxy-(3-phenyl)propylidene-Z-peroxy] 1.3-diisopropylbenzene. was kept in solution.

An isolated analytical sample had the following characteristics:

lodometric titration: 93.5%

Decomposition temperature: C.

Half-life at 104 C.: 30 minutes C (percent): found 71.9 (calculated 72.85)

H (percent): found 7.4 (calculated 7.74)

EXAMPLE 14 Into a flask provided with a stirrer were introduced 37 g. of a-a'-[2-hydroxy-(3-phenyl)propylidene-2- peroxy]-1.3-diisopropylbenzene (obtained according to Example 13) dissolved in 50 cc. of benzene and 50 cc. of ether. 45.2 g. of tert.-butyl hydroperoxide at and 20 g. ground anhydrous calcium chloride. This solution was then cooled to 5 C. and in over a 10 minute period there were added 20 g. of hydrochloric acid at 36%.

The exothermic reaction caused the temperature to rise to +5 C. and the solution was maintained at this temperature for one hour under stirring. Thereafter the organic phase was washed with water. with NaOH at 5%. and again with water until neutrality.

Then the solvent was removed under vacuum at 50 C.. thereby obtaining a slightly opalescent liquid residue (44 g.). identified as a-a'-[2-tert.-butyl-peroxy-( 3- phenyl)propylidene-2-peroxy]-1.3 diisopropylbenzene, having the following characteristics:

lodometric titration: 75%

Decomposition temperature: 132 C. Half-life at 123 C.: 30 minutes C (percent): found 72.9 (calculated 71.44) H (percent): found 8.5 (calculated 8.52)

EXAMPLE 15 Into a flask provided with a stirrer were introduced 50 cc. of benzene. 50 cc. of ethyl ether. 21.4 g. of 1.3- diisopropylbenzene-bis-hydroperoxide (sodium salt) at 67%, 19.3 g. of 4-tert.butyl-cyclohexanone. and g. of ground anhydrous calcium chloride; This mixture was then cooled and over a 20 minute period there were introduced dropwise 20 g. of HC1 at 36%. The mixture was then subjected to stirring for 1 hour at 5 C.

The organic solution was washed with water and was then dehydrated with anhydrous sodium sulfate. The residue (32 g. determined by analysis), identified as a-a-[l-hydroxy-(4-tert.-butyl) cyclohexylidene 1- peroxy]-l,3-diisopropylbenzene, was kept in a solution. An analytical isolated sample had the following characteristics:

lodometric titer: 95%

Decomposition temperature: 78 C.

Half-life at 110 C.: 30 minutes C (percent): found 71.3 (calculated 71.87)

H (percent): found 10.0 (calculated 10.18)

EXAMPLE l6 Into a flask provided with a stirrer were introduced 32 g. of a-a'[1 hydroxy-(4 tertbutyl)cyclohexylidene-l-peroxy]-1.3-diisopropylbenzene. dissolved in 50 cc. of benzene and 50 cc. ofether. and g. of anhydrous calcium chloride. Over a period of minutes there were then introduced into the mixture. at a temperature ofl 5 C.. 43.9 g. ofcumene hydroperoxide at 83.4%. The solution was again cooled to 15 C.. and there were introduced 10 g. of HC1 at 36% over a 10 minute period. The exothermic reaction caused the temperature to rise to 5 C. and the solution was then left under stirring for one hour at between 5 and 0 C.

The organic phase was washed with water. with NaOH at 5%, and then again with water until reaching neutrality. The solvent was then removed under vacuum at 50 C., thereby obtaining a slightly oily residue, identified as an a-a'-[1 cumyl-peroxy-(tert.- butyl)cyclohexyldiene-1-peroxy]-1.3-diisopropylbenzene, and it had the following characteristics:

lodometric titer: 90%

Decomposition temperature: 1 14 C.

Half-life at 125 C.: 30 minutes C (percent): found 75.1 (calculated 74.4)

H (percent): found 8.5 (calculated 8.52)

EXAMPLE 17 200 cc. of n-hexane. 50 g. of 1,3-diisopropylbenzenebis-hydroperoxide-sodium salt at 60%, 29 g. of aeetoacetic acid ethyl ester at 99% and 30 g. of ground anhydrous calcium chloride were introduced into a flask provided with a stirrer. The mixture was then cooled to 10 to 5C. and over a period of 30 minutes there were introduced 45 g. of HC1 at 36%. The mixture was then left under stirring for 1 hour at 5 C. The organic phase was then washed with water and thereafter was dehydrated with anhydrous sodium sulfate. The a-a-[- 2-hydroxy-( 3-ethoxy-carbonyl )-isopropylidene-2- peroxyl-l .3-diisopropylbenzene thus obtained (43 g. determined analytically) had the following characteristics:

lodometric titer:

Decomposition temperature: 47 C.

Half-life at 1 18 C.: 30 minutes C (percent): found 60.1 (calculated 59.24)

H (percent): found 7.65 (calculated 7.87)

EXAMPLE l8 Into a flask fitted with a stirrer were introduced 43 g. of a-a'-[2-hydroxy-(3-ethoxy-carbonyl)- isopropylidene-Z-peroxy]-1,3-diisopropylbenzene (obtained according to Example 17) dissolved in 200 cc. of n-hexane, 40 g. of tert.-butyl hydroperoxide at 75% and 40 g. of ground anhydrous calcium chloride. The solution was cooled to 10 C. and over a 10 minute period there were introduced 30 g. of HC1 at 36%. The temperature was allowed to rise to 0 C., and the solution was stirred for 1 hour at this temperature. The organic phase was then washed with water, then with NaOH at 5% and then again with water. The solvent was removed under vacuum, care being taken not to exceed 30 C.. thereby obtaining 47 g. of slightly yellow-coloured viscous residue identified as a-a-[ 2-tert.- butyl-peroxy-(3-ethoxy-carbonyl)-isopropylidene-2 peroxy]-1.3-diisopropylbenzene.

This product had the following characteristics:

lodometric titer: 97%

Decomposition temperature: 109 C.

Half-life at 1 18 C.: 30 minutes C (percent): found 61.4 (calculated 60.93)

H (percent): found 8.63 (calculated 8.63)

EXAMPLE l9 Into a flask provided with a stirrer were introduced 150 cc. of benzene. 23.5 g. of 1,4-diisopropylbenzenebis-hydroperoxide at 97.3%, 18 g. of acetoacetie acid ethylester at 99% and 10 g. of anhydrous calcium chloride. The mixture was then cooled to 10 C. and over a 5 minute period there were introduced 12 g. of HC1 at 36%. The mixture was then stirred at this temperature for 1 hour. The benzene phase was washed withwater and then treated with anhydrous sodium sulfate.

The a a [2 hydroxy (3-ethoxycarbonyl)isopropylidene-2 peroxy]-l.4-diisopropylbenzene thus obtained (29 g. analytically determined) had the following characteristics:

lodometric titer: 97%

Decomposition temperature: 45 C.

Half-life at C.: 30 minutes C (percent): found 58.6 (calculated 59.24)

H (percent): found 7.43 (calculated 7.87)

EXAMPLE 20 cc. of benzene containing 29 g. of a-a-[2- hydroxy-( 3 ethoxycarbonyl) isopropylidene 2 peroxy]-1.4-diisopropylbenzene (obtained according to Example 19) and 15 g. of anhydrous calcium chloride were introduced into a flask fitted with a stirrer. The

mixture was then cooled to 15C. and over a minute period there were introduced 43.9 g. of tert.-cumyl hydroperoxide at 83.4%. The temperature was maintained at 15 C. and over a 10 minute period there were introduced 10 g. of HCl at 3671. Due to the exothermic reaction the temperature rose to 5 C. and at this temperature the solution was then left under stirring for 1 hour. The organic phase was then washed with water, then with NaOH at 5% and again with water until neutrality. The solvent was removed under vacuum at C. thereby obtaining 38 g. of a slightly oily straw-colored residue identified as a-a'-[ Z-cumylperoxy (3-ethoxy carbonyl)-isopropylidene-Z-peroxy]- 1.4-diisopropylbenzenc having the following characteristics:

lodometric titer: 93%

Decomposition temperature: 121 C.

Half-life at 122 C.: 30 minutes C (percent): found 65.3 (calculated 66.82)

H (percent): found 7.32 (calculated 7.74)

EXAMPLE 21 vulcanization a,a-( 1-tert.-butyl-peroxy-cyclopentylidene-1- peroxy)-1.3-diisopropylbenzene;

a-a'-( 1-tert.-butyl-peroxy-4-tert.-butylcyclohexylidene-1-per0xy)-1.4-diisopropylbenzene:

a-a'-( 1-tert.-butyl-peroxy-cyclohexylidene-1- peroxy)-1.S-diisopropylbenzene;

a,a'-[ 2-tert.-hutyl-peroxy-( 3-ethoxycarbonyl isopropylidene-Z-peroxy]-1.3-diisopropylbenzene; dicumylperoxide.

The vulcanization rate was determined at 177 C. on

a Monsanto TM-10 rheometer. The mixes used in the test were of the following composition:

Ethylene-propylene copolymer parts 100 Carbon black do. ZnO do. 3 Sulfur do. 0.32 Peroxide mol. 0.01

Table 2 reports the physical characteristics of vulcanized products obtained by using as peroxides, respectively:

a-a'-( 1-tert.-butyl-peroxy-cyclopentylidene-1- Vulcanization tests were carried out on mixes of an 25 peroxy )-1,3-diisopropylbenzene; ethylene-propylene copolymer having a molar ratio a-a-( 1-tert.-buty1-peroxy-4-tert.-butylethylene/propylene 50/50 and a viscosity Mooney ML eyclohexylidene-1-peroxy)-1.4-diisopropylben- (1+4) 100 C.=35. In Table 1 there are compared the Zene; vulcanization rates determined on the same mixes. cona-a'-( l-tert.-butyl-peroxy-cyclohexylidene-ltaining as peroxides. respectively: 30 peroxy)-1,3-diisopropylbenzene;

TABLE 1 vulcanization rate vulcanization at tho Rheometer Parts 11003.0! Vulcaniethy anepmpylnation Vulcaniana capo ymar 00mm zatlon time. Peroxide typo G. Molal' 0. minutes CH; cm cnmcoo oob JJOO COOKIE); 0 4m 41H 0 CE CH; 0.79 0.01 177 4.6 rcnmcoo 00 l-boo 000mm 0H; CH0

CHr-C-CHI CHr-C-CHI CH; CH:

cal CH1 cn.).coo 005 100 000mm).

HI HI ,2-ter.-but 1 to: Mthox carbon 1190 r0 lldene-Z to: 1,8 dllso r0- fi ibenmifi'luff -3 "12.1"? -2 u 0.01 111 1 Dlcumylperoxldo 2.

EXAMPLE 22 On a mix having the following composition:

Ethylene/propylene copolymer parts 100 Carbon black do. 50 2110 do. 3 Sulfur do. 0.32 a-a'-l l-tcrt hutyl peroxy mol ().(ll

(3-ethoxycarhonyl )-isopropylideric-2-peroxy| L3 diisopropylhenzene the vulcanization test was carried out at 150 C. for 15 minutes. The vulcanized product showed the following physical characteristics:

Tensile strength (kg/cm?) I85 Elongation at break (percent) 412 Modulus at 200?! (kg/emf) (1i Modulus at 300% (kg/cm?) I08 l.R.H.D. hardness 67-68 EXAMPLE 23 Crosslinking stantially consisting of low-density polyethylene and peroxide.

In Table 3 there are recorded the physical characteristics of polyethylene crosslinked using the peroxides according to the invention, that is, a-a'-( l-tert.-butylperoxycyclopentylidenl -peroxy )-l .3-diisopropylbenzene, a a-(l-tert.-butyl-peroxy-4-tert.-butylcyclohexylidene-l peroxy)-l,4-diisopropylbenzene. and the known peroxide (dicumylperoxide).

EXAMPLE 24 The determination of the degree of swelling was carried out on the crosslinked product. By degree of swelling" is meant the volume of solvent absorbed per unit volume of crosslinked polyethylene.

The method consists of suspending a small basket or cage containing a crosslinked polyethylene plate of about 0.2 g. in a test tube containing l cc. of xylene stabilized with 0.l g. of the phenolic antioxidant 4,4- thio-bis-(3-methyl-6-tert.-butylphenol The test is carried out for 21 hours at 80 C. The degree of swelling (S) is determined from the following formula:

(ub)(' s=i.o7- +i wherein:

a=weight of the test sample after 21 hours at 80 C.

in xylene,

b=weight of the test sample before the test,

c=weight of the test sample after drying at the end of the test.

l.07=density of polyethylene at 80C./density of xylene at 80C.

The obtained results, compared with those in which The crosslinking tests were carried out on mixes sub- 40 dicumylperoxide was used. are listed in Table 4.

TABLE 8 crosslinking oi low-density (0.918) polyethylene physical characteristics :21 :18: crosslinking Elongat r g Time, Tempera 33:35 rim Peroxide ethylene minutes ture.C. kgJcmj kz-lcm. percent Nona 146 87.8 78 150 CH: CH: Hmooo 00$ $00 000 53, 6 lm. tlm V H] cm 0.01 20 52.7 137 m (C OICOO OOZCOO OOC(CH:)8

Q CH: J3

CE: CH:- CH:

Dicumylpunndn 0. 01 20 145 52. 9 m m Moles of peroxide Crowllnktna in 100 g.

01' poly- Time, Tempera- Degree of Peroxide ethylene minutes ture, C. swelllng 011i CH; (01105000 000 (i700 COP-(CHO! 6 All; CHa 6 CH, CH; 0. 01 M5 20. 2 tcmncoo cob-Gt 00 000mm)- 0E: (iHl CH- -CHo CH:- CH.:

(EH; JHQ

Dlmmylperoxlda 0. 01 20 145 21. 3

Variations can. of course, be made without departing from the spirit and scope of the invention.

Having thus described our invention, what we desire to secure by Letters Patent and hereby claim is:

1. A vulcanizable composition comprising an elastomer and a tetraperoxide of the formula l T R '-OO--Cl!-OO-X---OO'--(i-'OO--R wherein each R, is hydrogen or an alkyl, haloalkyl. cycloalkyl halocycloalkyl or alkylcycloalkyl group having 1-15 carbon atoms; aryl, haloaryl or alkaryl group having 6-15 carbon atoms; oxyalkyl, oxyalkylaryl or oxycycloalkyl groups having l-15 carbon atoms; each R is a carbalkoxy alkylene group wherein each alkylene group and each alkoxy group have 1-4 carbon atoms; each R is an alkyl or haloalkyl group having 4-12 carbon atoms; cycloalkyl, halocycloalkyl or alkylcycloalkyl group having 4-21 carbon atoms; aryl, alkaryl or haloaryl groups having 6-24 carbon atoms; oxyalkyl, oxyalkylaryl or oxycycloalkyl groups having 4-24 carbon atoms; or an acyl group having 6-12 carbon atoms; and X is an alkylenc, haloalkylene or arylalkylene group having 2-18 carbon atoms; an alkenylene. haloalkenylene or arylalkenylene group having 2-18 carbon atoms; an alkinylene, haloalkinylene or arylalkinylene group having 2-18 carbon atoms; an oxyalkylene group having 2-18 carbon atoms; or an arylene. alkylarylene or haloarylene group having 6-18 carbon atoms.

2. The composition of claim 1 wherein the elastomer is an ethylene/propylene copolymer.

3. The composition of claim 1 wherein the quantity of peroxide present is from about 0.5 to 10% based on the elastomer.

4. The composition of claim 2 further comprising, per parts of ethylene/propylene copolymer. from 20 to 80 parts of carbon black. from 1 to 10 parts of ZnO or MgO. and from 0.15 to 5 parts of sulfur.

5. A process for vulcanizing the composition of claim 4 comprising heating to a temperature of from about to C for periods from about 5 to 200 minutes. 6-. The vulcanized product of the process of claim 5. 7. A crosslinkable composition comprising a plastomer and a tetraperoxide of the formula l f R -oo-coo-x-0oc-oo-R wherein each R, is hydrogen or an alkyl, haloalkyl, cycloalkyl, halocycloalkyl or alkylcycloalkyl group having 1-15 carbon atoms; aryl, haloaryl or alkaryl group having 6-15 carbon atoms; oxyalkyl, oxyalkylaryl or oxycycloalkyl groups having 1-15 carbon atoms; each R is a carbalkoxy alkylene group wherein each alkylene group and each alkoxy group have l-4 carbon atoms; each R is an alkyl or haloalkyl group having 4-12 carbon atoms; cycloalkyl, halocycloalkyl or alkylcycloalkyl group having 4-21 carbon atoms; aryl, alkaryl or haloaryl groups having 6-24 carbon atoms; oxyalkyl, oxyalkylaryl or oxycycloalkyl groups having 4-24 carbon atoms; or an acyl group having 6-12 carbon atoms; and X is an alkylene, haloalkylene or arylalkylene group having 2-18 carbon atoms; an alkenylene, haloalkenylene or arylalkenylene group having 2-18 carbon atoms; an alkinylene, haloalkinylene or arylalkinylene group having 2-18 carbon atoms; an oxyalkylene group having 2-18 carbon atoms; or an arylene. alkylarylene or haloarylene group having 6-18 carbon atoms.

8. The composition of claim wherein the plastomer is polyethylene.

9. The composition of claim 7 wherein the quantity of peroxide present is from about 0.5 to 10% based on .the plastomer.

10. A process for crosslinking the composition of claim 9 comprising heating to a temperature of from about 100 and 200C for a period of from about 5 to 60 minutes at a pressure of from about 50 to 200 kg/cm 11. The crosslinked product of the process of claim 10. l l

UNZTED STATES PA ENT ()FFEQE vfimfi'fii 1 n (in I QlLltlAE'lkCPALL 3L b8 lftl ml UL Patent No. 3, 878, 161 Dated April 15 1975 Inventcr(s) Egeo SACRINI and Claudio CAVALLOTTI It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

title page, under "Related U.S. Application Data": "August 8, 1970" should read August 7, 1970 title page, under "Foreign Application Priority Data": "20839/69" should read 20839-A/69 title page, under the Abstract, line 1 after the formula: "where" should readwherein line 7 after the formula "monohydroxide. should read monohydroperoxide.

Column 1, lines 1-3: The title should read: ORGANIC PEROXIDES, THEIR PREPARATION AND THEIR APPLICATION line 5: "August 8, 1970" should read August 7, 1970 lines 35-37:

"R OOC-OO-X-OO-(IJ-OO-R shOuld read R R 1 i R R 2 3 Column 2, lines 1-2: "cited general formula" should read cited formula Column 3, lines 1-2: "on-o3 i2-hydroxy(B-ethoxycarbonyl) isopropylidene-Z-peroxy]l, 3-diisopropylbenzene; should read ova-[2-hydroxy(B-ethoxycarbonyl)isopropylidene-Z- peroXy] l,4diisopropylbenzene; line 39: "2,5-dimethyllg U1 T531) STATES PATENT OF 1 1C P \J 1, 3 I

Y (w v T i T3 15' ""TQ C1311 i ll lmATm Oi (30.1mm: i 1N Patent No. 3,878,161 Dated April 15, 1975 Inventor(s) Egeo SACRII'EI and Claudio CAVALLOTTI Page It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

[- 2,S-dihydroperoxide-hexene-B; should read 2,5-

dimethyl-Z,5-dihydroperoXide-hexane-3;

Column 4, lines 38-39: "a,oL-[2-cumyl peroxy-(B-ethoxycarbonyl) isopropylidene-Z-peroxy]-l,4diisopropylbenzene; should read a-cz-{Z-cumyl peroxy- (ethoxycarbonyl)- isopropylidene-Z-peroxy]-l,4-diisopropylbenzene; lines 48-49: "(x-on- (l-tert.buty1 peroxy-cyclohexylidene-lperoxy) l, B-diisopropylbenzene; should read (IL-q- (l-tert.-butyl peroxy-cyclohexylidene-l-peroxy) -1,3- diisopropylbefnzene; x

Column 5, line 38: "paraticularly" should read particularly Column 8, lines 20-21: '1, 3-diisopropylbenzenebishydroperox'lde" should read l,3-diisopropy1benzenebis-hydroperoxide lines 67-68: "1, 3-diisopropy1benzenebishydroperoxide" should read 1,3-diisopropylbenzenebis-hydroperoxide Column 9, line 10: "l,3-diisoprophylbenzene" should read l, 3-diiso'propy1benzene line 36: trimethylnonylidene-" should read trimethyl-nonylideneline 1.) H 111,1 1 1;, .J" .1..,....': .1 .1 ,,1

- w baluulqecu DLLUu-LLJ. .Lcau Calou. aLCd Columns 13-14, at the bottom of the table: "a-a2-t er. butylperoxy(3-ethoxycarbonyl) should read a-oL' [Z-ter. butylperoxy(B-ethoxycarbonyl) Column 17, line 28: "showed" should read had Signed and Scaled this twenty-first D ay 0 f October 19 75 [SEAL] A ttes t: 

1. A VULCANIZABLE COMPSOITION COMPRISING AN ELASTOMER AND A TETRAPEROXIDE OF THE FORMULA
 2. The composition of claim 1 wherein the elastomer is an ethylene/propylene copolymer.
 3. The composition of claim 1 wherein the quantity of peroxide present is from about 0.5 to 10% based on the elastomer.
 4. The composition of claim 2 further comprising, per 100 parts of ethylene/propylene copolymer, from 20 to 80 parts of carbon black, from 1 to 10 parts of ZnO or MgO, and from 0.15 to 5 parts of sulfur.
 5. A process for vulcanizing the composition of claim 4 comprising heating to a temperature of from about 140* to 190*C for periods from about 5 to 200 minutes.
 6. The vulcanized product of the process of claim
 5. 7. A crosslinkable composition comprising a plastomer and a tetraperoxide of the formula
 8. The composition of claim 7 wherein the plastomer is polyethylene.
 9. The composition of claim 7 wherein the quantity of peroxide present is from about 0.5 to 10% based on the plastomer.
 10. A process for crosslinking the composition of claim 9 comprising heating to a temperature of from about 100 and 200*C for a period of from about 5 to 60 minutes at a pressure of from about 50 to 200 kg/cm2.
 11. The crosslinked product of the process of claim
 10. 